Balance/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby An overhead view shows Tim and Moby in a spinning teacup ride. The ride stops and Tim walks away groaning. TIM: Ugh...I think I'm going to lose that hot dog... Moby hands Tim a letter. MOBY: Beep. Tim reads from the typed letter. TIM: Dear... Dear Tim and Moby, how come I get dizzy when I spin around? From, Lyle. Let's just– Moby grabs Tim before he can walk away. MOBY: Beep. Moby and Tim are seated back in the teacup. TIM: I really don't think this is a good idea. An image shows a diagram of the inner ear. TIM: Spinning around causes a disturbance in your inner ear, or labyrinth, where your sense of motion and balance are regulated. The labyrinth is two systems of fluid-filled passages that detect sound and motion. An image shows the two passages that detect sound and motion. TIM: The motion-detecting passages are called the vestibular system. It's made up of five parts: the utricle, the saccule, and three semicircular canals. The image shows a diagram of the vestibular system. The five parts are labeled. TIM: The utricle and saccule contain tiny crystals that rest on a thick layer of gel. The image shows what Tim describes. Moby and Tim's teacup begins to spin. TIM: When you accelerate, or speed up, in any direction, the crystals move along the gel, disturbing the hairs below. These cells are attached to nerves, which send out signals to the eyes and brains whenever the hairs move. Animations illustrate the crystals shifting, moving the hairs and triggering an electrical reaction in the nerves.. TIM: That's how you know when you're moving. An animation shows Tim inside the tea cup as it spins around. TIM: To-to locate our position in space, three semicircular canals monitor rotational movement. Those canals are arranged at right angles to each other, corresponding to the three dimensions of space. Images and animations detail the semicircular canals as Tim describes. TIM: When you move your head in any direction, or turn your body around, it moves fluid inside the canals, stimulating hair cells that grow inside. Nerve signals from the hair cells go to the brain, the muscles that control your posture, and your eyes. Your eyes rely on these signals for information on where to look. An animation shows the movement of fluid and stimulation of hair cells inside the canals. Nerve signals send signals to other parts of the body. TIM: They're constantly making small adjustments to where they focus based on signals from the vestibular nerve. An animation shows a pair of eyes looking around. TIM: That's why spinning around messes up your vision. The fluid in your semicircular canals is moving, and your eyes are trying to follow that movement. A split screen animation shows the eyes moving as the motion of the fluid triggers nerve signals. MOBY: Beep. Tim has double vision and blurriness when he looks at Moby in the spinning tea cup. Tim's face turns green. TIM: Ugh. The-The reason you might feel sick is because the signals from your ear conflict with signals from the rest of your body. MOBY: Beep. TIM: See, your sense of balance doesn't just come from your inner ear. It's really an interpretation of signals from all over your body. An image shows a man walking on a tightrope and holding on to a pole for balance. TIM: Your inner ear monitors motion and acceleration, signals from your eyes tell you exactly where you are in space, skin pressure receptors signal what parts of your body are touching the ground, and which way is down, muscle receptors signal which parts of your body are moving, and all of these signals are sent to the spinal cord and brain, where logical sense can be made of them. Animations show the inner ear, eyes, soles of the feet, leg muscles, spinal cord, and brain inside the man on the tightrope. TIM: So when you stop spinning, the moving fluid in your inner ear tells your brain that you're still moving, but your eyes and muscles tell it that you're standing still. Images show the fluid moving, the eyes, and the leg muscle as Tim explains. TIM: And that's when you start to feel sick. The spinning tea cup ride slows down and stops. Tim's face is green. MOBY: Beep? TIM: Uh, yeah. I guess I'm okay. Tim tries to stand up and gets dizzy. TIM: On second thought, I'm just going to hang here for a second. Uhhhhh...... Category:BrainPOP Transcripts Category:BrainPOP Health Transcripts